The U.S. economy isn't expanding fast enough for the Federal Reserve to reduce its stimulus efforts at this time, the Federal Open Market Committee announced Wednesday.

The decision means that the central bank will continue buying $40 billion of mortgage-backed securities and $45 billion of longer-term treasury securities each month. The Fed will also keep a key interest rate at or near 0 percent. The moves work to pump money into the economy while also keeping mortgage and other rates at historic lows.

Fed Chairman Ben Bernanke said in a news conference after the announcement that there was no set plan to end the programs, meaning that if the economy picks up or loses steam, the Fed would adjust. However, Bernanke said a consensus exists among the committee members that the bond-buying likely would become scaled back by the end of this year and end in mid-2014, when the U.S. unemployment rate is around 7 percent. In May, the jobless rate was at 7.6 percent.

A statement released by the FOMC says the central bank won't raise interest rates as long as unemployment remains above 6.5 percent. Bernanke said 14 of its 19 members believe that won't happen until 2015, while another says it won't come until 2016.

Bernanke said the economy was continuing to expand, despite its biggest headwind: 1.5 percent federal budget cuts that he said have yet to make their full impact.

Some analysts had expected the Fed would begin scaling back the stimulus this month.

Economists in San Diego had mixed reactions to the news.

Alan Gin, economist at the University of San Diego, said he thinks the economy still needs a boost. He noted the modest 175,000 payroll jobs added across the country in May. He said job gains should be in the 200,000s each month to indicate a growing economy.

"The economy is not completely out of the woods," he said. "There are some improvements, but it's still not where we want to go, so I think continued stimulus on the monetary front is necessary."

But Kelly Cunningham, economist at the National University System Institute for Policy Research, said the Fed should have started to scale back the stimulus because it is making the country vulnerable to inflation.

"When they start to pull back I think that’s going to cause a huge disruption in the economy," he said. "We need to go through that as a country, as an economy, and I think it'd be better to take our medicine now rather than postponing it. We just need to get off this artificial stimulus."

Lynn Reaser, chief economist at Point Loma Nazarene University, said she wasn't surprised by the move.

"I did not think that they had enough evidence of a 'substantial improvement' in the labor markets," she said in an email. "Today's announcement, however, does indicate that the Fed thinks that there will be enough evidence to reduce asset purchases by year-end."